The present invention relates to an automatic distributor in an appliance for brewing or infusing beverages, for distributing powdered product that will be infused, percolated, or brewed, the powdered product being, for example, ground coffee, tea, cocoa, etc.
An appliance for the preparation and distribution of hot beverages generally includes a cold water reservoir, an electric pump, a boiler, and an infusion, or brewing, head arranged to receive the ground product in order to inject therein hot water coming from the boiler, the resulting beverage then being directed toward a collecting vessel. At the end of the infusion cycle, the infusion head must be opened in order to be able to introduce therein a new quantity of powdered product after having removed the product remaining after a previous infusion.
Such an appliance is described in the patent document WO 99/12457, the disclosure of which is incorporated herein by reference, which relates to an appliance arranged to automatically distribute espresso coffee made from coffee grounds. The appliance has an infusion group composed of an infusion chamber having a vertical axis arranged to receive a pressing piston that slides along the vertical axis and is actuated by the piston of a hydraulic piston-cylinder unit. The latter piston is connected to the pressing piston and can pass from a rest position to a work position in which the pressing piston is driven into the infusion chamber under the influence of the hydraulic fluid in the cylinder. Return to the rest position is effected by a return spring.
This appliance also includes an automatic distributor of grounds having a reservoir containing the grounds and provided with a distribution opening, a chute conducting the grounds toward the infusion chamber, and a hub connected to a shaft that rotates paddles carried by the hub in order to push a certain quantity of grounds into the chute via the distribution opening when the hub is being rotated. Such an automatic distributor of grounds is described in the French patent document FR 2713906, the disclosure of which is incorporated herein by reference.
Although this appliance functions satisfactorily, it has nevertheless been observed that clumps of coffee appear in the channel that conducts the grounds from the distributor toward the infusion chamber. In effect, after producing several successive batches of coffee, the infusion chamber releases moisture in the form of steam. The chute along which the coffee grounds descend being situated in proximity to the infusion chamber, the steam released in the chamber condenses on the walls of the chute, thus promoting adherence of the coffee grounds or powder. These grounds or powder then accumulate on the walls of the chute, with the result that, after several coffee brewing cycles, coffee can collect on the chute and between the chute and the infusion chamber, the accumulations being larger in the case of finer coffee grounds.
Moreover, the patent document WO 03/013324, the disclosure of which is incorporated herein by reference, describes another ground coffee dosing device arranged in the housing of a coffee machine having an infusion chamber supplied from the chute of the device, whose inlet opening opens to the outside of the housing. The ground coffee dosing device has a trap door movably mounted in the upper part of the chute and arranged to determine a dosing volume corresponding to the volume of the infusion chamber. The trap door is pivotally mounted in the chute and is actuated by the movement of a control rod connected to the pivot structure of the lid. The rod in particular has an end stub mounted in an articulating manner on the lid having the form of a domed pin in which, besides its function of driving the trap door, performs the supplementary function of scraping the upper surface of the latter. However, such a device actuated by the manual opening of the lid is not adapted to the function of an automatic distributor of beverages where most of the functions are automated.